The present invention relates generally to electrostatic discharge protection devices for semiconductors and more specifically to shorting bar electrostatic discharge protections.
A semiconductor integrated circuit is susceptible to electrostatic discharge (ESD). Most circuits have built-in circuitry to protect them from large electrostatic discharges when the integrated circuit is mounted or installed in there end use. To protect integrated circuits from electrostatic discharge, prior to being assembled in a circuit and during shipping and, it is common practice in the industry to provide a shorting bar which extends across the leads of a semiconductor package in a package carrier to short the leads to each other. If these packages are inserted in a tester, the shorting bar is removed from the leads to allow testing. Once the packages are removed from the tester, they require manual reset. All to often, the test operator fails to reset the shorting bar, therefore the package becomes susceptible to destruction by electrostatic discharge. A typical example is part number 7-0132-10655-940-XXX-000 from 3 m Textool. Thus, there is a need for a fully automatic shorting bar mechanism to protect the semiconductor package.
Thus, it is obvious of the present invention to provide a fully automatic shorting bar mechanism for a semiconductor packages.
Further, it is the object of the present invention to provide a shorting bar assembly which is inexpensive and easy to assemble as well as fully automatic.
These and other objects are achieved by providing a shorting bar and a package carrier for a semiconductor package which includes the shorting elements and a biasing element for biasing the shorting elements into engagement with the leads. An actuator is provided for automatically overcoming the biasing and causing the shorting elements to disengage the leads in response to the package carrier being mounted to a tester and automatically resetting to allow the biasing to cause a shorting bars to engage the leads in response to package being removed from the tester. The shorting element includes a plurality of shorting elements, one for each set of leads extending from a respective side of the package and preferably is a unitary structure. The actuator and the biasing means are also formed as a unitary structure with the shorting elements. The actuator extends from the shorting elements and into a first opening in a first wall of the housing allowing it to be responsive to its position relative to the tester. The biasing element extends from the end of the actuator to a second wall of the housing for biasing the actuator to extend into the first opening and the shorting elements onto the leads. The second wall also has a second opening into which the shorting elements extend when disengaged from the leads.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.